Re: Add `ly:undead?' to predicate list. (issue 93660047)

[dak]

On 2014/06/01 18:09:12, Mark Polesky wrote:
> On 2014/06/01 15:10:59, dak wrote:
> > scm/lily.scm:728: (,ly:undead? . "undead object")
> > Probably more like an "undead container" as the undead thing (to
survive
> between
> > sessions) is placed inside.
> >
> > Won't be helpful information to somebody reading the manual which is
the
> reason
> > I'm somewhat unenthusiastic including it.  On the other hand, there
are lots
> of
> > predicates sharing that deficiency.

> I never thought that the tiny predicate docstrings in
> lily.scm were so much about documentation; we have
> docstrings in lily/*.cc for that (IR 4: "Scheme functions")
> -- and those descriptions can be longer if needed for
> clarity.

> I thought that the docstrings in lily.scm are primarily
> there for error reporting:
> "wrong type for argument ~a.  Expecting ~a, found ~s"

> They have the added benefit of a little clarification in the
> Notation appendix "Predefined type predicates", but I
> wouldn't want the error reporting to be too wordy.

> In either case, if my pretty-print patch goes through, then
> the lilypond-exported-predicates alist will also be used to
> define (ly-type? x).  I don't know if an undead container
> would ever be the default value of some grob property in the
> future, but if it were, I wouldn't want it mistakenly
> prepended with a single-quote in the IR, which is what could
> happen with my other patch if we leave any predicates off of
> the list.

> - Mark

You are right about the error message stuff -- didn't think about that.
Undead containers are only used in session management so we would not be
seeing them in properties.  At any rate, makes probably more sense to go
ahead with this patch rather than not.

https://codereview.appspot.com/93660047/